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Biomedical subjects

S Harada

Publications and source records attributed to S Harada.

At least 559 records · Page 31Linked to original sources
PubMed1986

[Progressive left ventricular dilatation in a child with hypertrophic cardiomyopathy: a case report].

Clinical pictures of a patient with progression from hypertrophic cardiomyopathy to dilated cardiomyopathy features in the end stage was described. Echocardiography performed at the age of five years revealed septal hypertrophy without systolic anterior motion (SAM). At 7 years of age, it revealed ventricular septal thickness of 18 mm, left ventricular posterior wall thickness of 24 mm, and marked SAM. Echocardiography at 14 years of age revealed left ventricular dilatation (52 mm in diastole) with poor contraction. Ventricular septal thickness was 18 mm and left ventricular posterior wall thickness was 16 mm. The SAM was no longer present. At autopsy, the heart weighed 590 g, and there was moderate dilatation of the right and left ventricular cavities. Histologically, there were massive fibrosis and myocardial disarray in the right and left ventricular walls.

Cardiomyopathy, Dilated↗
PubMed1986

Relation of hydrolytic enzymes in spleen to immunological dysregulation in mice.

In order to know the role of hydrolytic enzymes in various immunological disturbances, we compared the enzymatic changes in the spleens of nude mice and NZB/W mice relative to their respective controls. In spite of the different immunological features of these models, multivariate analysis demonstrated that there is some commonness in enzymatic changes between the two models. The enzymes related to such commonness included glycosidases, alkaline phosphatase, fMet-AP, and esterase. These enzymes may play some important roles in immunologic dysregulation , especially in relation to B-cell dominance in these disease models.

Animals↗
PubMed1986

Aldehyde dehydrogenase polymorphism in North American, South American, and Mexican Indian populations.

While about 40% of the South American Indian populations (Atacameños, Mapuche, Shuara) were found to be deficient in aldehyde dehydrogenase isozyme I (ALDH2 or E2), preliminary investigations showed very low incidence of isozyme deficiency among North American natives (Sioux, Navajo) and Mexican Indians (mestizo). Possible implications of such trait differences on cross-cultural behavioral response to alcohol drinking are discussed.

Aldehyde Dehydrogenase↗
PubMed1985

Infection of human T-lymphotropic virus type-I (HTLV-I)-bearing MT-4 cells with HTLV-III (AIDS virus): chronological studies of early events.

Early events in the infection of the human T-lymphotropic virus type-I (HTLV-I)-positive MT-4 cell line by the acquired immune deficiency syndrome (AIDS) retrovirus HTLV-III were investigated. The virus was adsorbed completely to the cells within 60 min incubation after inoculation of the virus. Then, infected MT-4 cells started to produce the HTLV-III-specific antigens between 12 and 24 hr postinfection. Synthesis of the viral antigens consisting of 120K, 46K, 24K, and 17K polypeptides was suppressed by the treatment of the virus-infected MT-4 cells with cytosine arabinoside (Ara-C) or by the treatment of the virus with anti-HTLV-III-positive sera. The progeny of the virus released from the infected MT-4 cells was titrated by a newly developed plaque-forming assay method and reverse transcriptase activity. The maximum activity of HTLV-III (3 X 10(5) PFU/ml) was observed on Days 4 and 5 p.i. Most of the viral activities in this preparation were ascribed to HTLV-III, and not to HTLV-I. No phenotypic mixing between HTLV-III and HTLV-I was discerned, although MT-4 cells were HTLV-I-producer cell line. Thus, HTLV-III-infected MT-4 cells are thought to be useful in further study of the interaction between host cells and the virus, and appear to be a good viral source for the analysis of the virus.

Adsorption↗
PubMed1985

Selective cytotoxicity of AIDS virus infection towards HTLV-I-transformed cell lines.

Previously, we reported that cells of the human T-cell lymphotropic virus type I (HTLV-I)-transformed lines MT-2 and MT-4 were extensively killed by infection with AIDS retrovirus HTLV-III. We have investigated this phenomenon more systematically using light and electron microscopy as well as immunofluorescence. The cell lines used in the present studies included 14 of those carrying not only human HTLV-I but also related simian agents and 6 HTLV-I-negative T- and B-cell lines. The results showed that the cytocidal effects occurred in the HTLV-I-transformed cell lines exclusively and were not present in further subcultures. In these cell lines the cytotoxic response was closely correlated with the induction of HTLV-III antigens after virus infection. However, cells of 6 HTLV-I-free lines were not killed to a marked extent by HTLV-III and were passaged as continuous producers of AIDS virus. Only 2 cell lines were resistant to the cytocidal effect of HTLV-III among 14 HTLV-I carrying cell lines. They were also resistant to the replication of infected HTLV-III. This AIDS virus-specific cytotoxic effect observed in HTLV-I-transformed cell lines did not appear to be associated with gene expression of the gag and pXs region of HTLV-I genomes. This result may indicate that HTLV-III specifically interferes with some steps of HTLV-I transformation.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Host cell range of adult T-cell leukemia virus. I. Viral infectivity and binding to various cells as detected by flow cytometry.

Adult T-cell leukemia virus is the member of a human type-C retrovirus family (HTLV) found to be associated with adult T-cell leukemia (ATL) in Japan. In our study, HTLV was isolated from the MT-2 cell line, purified on sucrose gradient and labelled with fluorescein-isothiocyanate (FITC-HTLV). The protein pattern of the virus was determined by SDS-gel electrophoresis and assured by Western blotting using ATL patient serum. Fresh human lymphocytes, separated B and T cells, mouse and rabbit lymphocytes, mouse fibroblasts, and 13 different tumor cell lines were tested in parallel for binding of FITC-HTLV and infectability by the virus. Virus binding to cell receptors was assayed by flow cytometry. Successful infection was monitored by following the expression of HTLV-determined antigen (HTLA). Most of the cells bound FITC-HTLV at levels ranging from 5% to 130% of the MT-2 cell binding. Only fresh human T, mouse and rabbit lymphocytes were infectable by cell-free virus preparations. The results demonstrate that HTLV receptors are present on different types of cells of both human and animal origin, and that infection by the virus is restricted to fewer host cells but not limited to a specific class of human lymphocytes.

Animals↗
PubMed1985

Infection of HTLV-III/LAV in HTLV-I-carrying cells MT-2 and MT-4 and application in a plaque assay.

The human T-cell lines MT-2 and MT-4 carry the human T-cell leukemia virus type I (HTLV-I). When MT-2 and MT-4 were infected with HTLV-III, the probable etiologic agent of the acquired immune deficiency syndrome (AIDS), rapid cytopathogenic effects and cytotoxicity were observed that made it possible to titrate the biologically active virus in a plaque-forming assay. The cytopathogenic effects were preceded by the rapid induction and increase of HTLV-III antigens as revealed by immunofluorescence and immunoprecipitation. Activities of HTLV-III were neutralized by the human antibodies against the virus when immunofluorescence and plaque assays were used. Essentially the same results were obtained with the lymphadenopathy-associated virus (LAV1).

Adult↗
PubMed1985

Monoclonal anti-human IgG antibodies for quantitation of allergen-specific IgG in human sera.

Eight monoclonal anti-human IgG antibodies were fully characterized and evaluated as possible reagents in solid phase radioimmunoassay for quantitating allergen-specific IgG antibody. Four monoclonal antibodies (HG24D, HG2-14, HG2-18, and HG2-25) recognize CH2 domain of human IgG and bind to human IgG fixed to microtiter plate with high affinities. These monoclonal antibodies were more suitable than polyclonal rabbit anti-human IgG antibody in Phadebas RAST for honey bee venom-specific IgG antibody. Nonspecific binding was much lower, and the slopes of standard curves were much steeper. In contrast to polyclonal antibody, the standard curve was hardly influenced by human serum IgG in sample diluent. These advantages of monoclonal antibodies that recognize CH2 domain of human IgG made it possible to quantitate egg white- and Dermatophagoides pteronyssinus-specific IgG antibodies with use of allergen disks prepared for IgE RAST. This property allows a single system to be used for measurement of IgG and IgE antibodies against clinically relevant allergens.

Allergens↗
PubMed1985

Catalogue of Epstein-Barr virus (EBV) receptors on human malignant and non-malignant hematopoietic cell lines.

Epstein-Barr virus (EBV) can induce a broad spectrum of hematological diseases, especially in immune deficient patients. We assayed for receptor for EBV (EBVR) using fluoresceinated viral particles on 44 human hematopoietic cell lines derived from patients with T, B, and non-T, non-B acute lymphocytic leukemia (ALL), non-lymphoid leukemia, Burkitt lymphoma, myeloma and several unique lines we and others have recently developed. All 31 EBV nuclear-associated antigen (EBNA) negative cell lines were of neoplastic origin. Seven of 13 EBNA-positive cell lines were of normal cell origin. Four of 25 non-B (surface immunoglobulin negative) EBNA-negative neoplastic cell lines were EBVR-positive. Three of six EBNA-negative B-cell (surface immunoglobulin positive) lines were EBVR-positive. Nine of 13 EBNA-positive Burkitt and non-Burkitt cell lines strongly expressed EBVR. Four EBNA-positive Burkitt lymphoma cell lines exhibited EBVR only to a limited degree. Studies of the cell lines for EBVR, complement receptors (CR) and surface immunoglobulin (SIg) revealed that presence of SIg does not obligate the presence of EBVR. Functional EBVR accompanied SIg among EBNA-negative cell lines. SIg-negative cell lines can possess EBVR. Fourteen of 16 EBVR-positive lines were also positive for CR. The EBVR assay is a useful tool for assessing the potential role of EBV in the induction of hematopoietic disorders.

Antigens, Surface↗
PubMed1985

Structure of ferricytochrome c' from Rhodospirillum rubrum at 6 A resolution.

The structure of a ferricytochrome c' extracted from Rhodospirillum rubrum has been determined at 6 A resolution by the X-ray crystallographic method. The crystals, obtained by dialyzing the protein solution against polyethylene glycol 4000, belong to the hexagonal space group P6(1). Two heavy atom derivatives were obtained by soaking the native crystals in K2PtCl6 and CH3HgCl solution. The phases calculated by the multiple isomorphous replacement method gave an overall figure of merit of 0.90 at 6 A resolution. The resulting electron density map showed the molecular boundary clearly, and gave molecular dimensions of 50 X 25 X 30 A for a monomer molecule. From visual examination of this map, the cytochrome c' from Rhodospirillum rubrum has a similar chain-folding pattern to the cytochrome c' from Rhodospirillum molischianum, the structure determination of which has already been carried out.

Crystallography↗
PubMed1985

Lymphocyte subsets in HLA-DR2-positive narcoleptic patients.

On the basis of our recent finding that all narcoleptic patients were HLA-DR2 positive, peripheral blood lymphocyte subsets were examined in 30 HLA-DR2 positive narcoleptic patients by using monoclonal antibodies and a flow cytometry. The percentages of OKIa1+ cells and OKM1+ cells increased significantly, while no quantitative changes were observed in the T cell subsets examined in the present study. No major immunological abnormalities which altered the T cell subpopulations quantitatively were apparent in narcolepsy.

Adult↗
PubMed1985

Effect of heat and fresh human serum on the infectivity of human T-cell lymphotropic virus type III evaluated with new bioassay systems.

MT-4 cells, which are a human T-cell lymphotropic virus type I (HTLV-I)-positive cell line highly permissive to HTLV-III infection, were used to detect the biologically active virus. For quantitation of the virus, induction of HTLV-III-specific antigen(s) and inhibition of DNA synthesis in infected MT-4 cells were assessed by indirect immunofluorescence and by a proliferation assay measuring [3H]thymidine uptake, respectively. HTLV-III was fully inactivated by treatment at 56 degrees C for 30 min. It was not inactivated by treatment with fresh anti-HTLV-III-negative serum. Thus, these assay systems with MT-4 cells would be useful in further studies on acquired immune deficiency syndrome.

Biological Assay↗
PubMed1985

Diffuse peripheral lung disease: evaluation by high-resolution computed tomography.

High-resolution computed tomography (HRCT) was performed on 15 patients who had diffuse peripheral lung disease, and the findings were compared with those of conventional chest radiography and histologic examination. Bullae, interstitial fibrosis with honeycombing, and small granulomas were more clearly and specifically demonstrated on HRCT scans than on conventional chest radiographs in all patients. Histologically proved mild alveolar wall thickening due to alveolitis in cases of sarcoidosis and systemic lupus erythematosus was not detected. HRCT is useful for performing detailed morphological analyses of abnormalities of the peripheral portions of the lung.

Adult↗
PubMed1985

Formadicins, new monocyclic beta-lactam antibiotics of bacterial origin. I. Taxonomy, fermentation and biological activities.

A Gram-negative bacterium produces new monocyclic beta-lactam antibiotics with a formylamino substituent, named formadicins A, B, C and D. The producing bacterium was taxonomically characterized and designated as Flexibacter alginoliquefaciens sp. nov. YK-49. Formadicins have narrow antibacterial spectra. They are highly active against some species of Pseudomonas, Proteus and Alcaligenes. Of the four, formadicin C shows the most potent antibacterial activity. Several amino acids such as glycine, D-alanine and D-leucine were antagonistic against formadicins. Formadicins, especially formadicins A and C having the formylamino substituent bound to the 3-position of a beta-lactam nucleus, were highly resistant to hydrolysis by various types of beta-lactamases. Formadicins A and C showed affinity for penicillin-binding proteins (PBPs) 1A and 1B in Pseudomonas aeruginosa IFO 3080, but formadicin B and nocardicin A showed affinity only for PBP 1B. Formadicins A and C did not lyse Escherichia coli LD-2 solely at their MICs, but when combined with mecillinam each induced a rapid lysis of this organism.

Amino Acids↗
PubMed1985

Formadicins, new monocyclic beta-lactam antibiotics of bacterial origin. II. Isolation, characterization and structures.

New monocyclic beta-lactam antibiotics, formadicins A, B, C and D, were isolated from the culture filtrate of Flexibacter alginoliquefaciens sp. nov. YK-49 by various types of column chromatography and preparative reverse-phase HPLC. Their structures were determined by spectroscopic analyses and degradation studies. They have a nocardicin-type skeleton and a formylamino group at the 3- or 12-position. Formadicins A and B each have a D-glucuronide moiety and give formadicins C and D, respectively, upon hydrolysis using beta-D-glucuronidase.

Anti-Bacterial Agents↗